[POWERPC] Uninline and export virq_to_hw()

Uninline virq_to_hw and export it so modules can use it.  The alternative
would be to export the irq_map array instead, but it's an infrequently
called function, and keeping the array unexported seems considerably
cleaner.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/irq.h b/include/asm-powerpc/irq.h
index 4734cc1..05dd5a3 100644
--- a/include/asm-powerpc/irq.h
+++ b/include/asm-powerpc/irq.h
@@ -138,10 +138,7 @@
 
 extern struct irq_map_entry irq_map[NR_IRQS];
 
-static inline irq_hw_number_t virq_to_hw(unsigned int virq)
-{
-	return irq_map[virq].hwirq;
-}
+extern irq_hw_number_t virq_to_hw(unsigned int virq);
 
 /**
  * irq_alloc_host - Allocate a new irq_host data structure